Full time four wheel drive

ABSTRACT

Four wheel drive train including a transfer case adapted to provide full time four wheel drive. A differential is provided in the transfer case and, if desired, the differential may be locked up to prevent differentiation.

United States Patent 1 1 1 3,848,691

Dolan Nov. 19, 1974 FULL TIME FOUR WHEEL DRIVE 3,492,890 2/1970 Hill et al. 180/44 R x [75] Inventor: Courtney F. Dolan, Syracuse, NY.

[73] Assignee: Chrysler Corporation, Highland Primary EXaml-ner M. Henson wood Park, MlCh- Assistant ExaminerGene A. Church 22 i Oct. 24 1973 Attorney, Agent, or Firm-Talburtt & Baldwin [21] Appl. No.: 409,342

Related US. Application Data [63] Continuation of Ser. No. 311,045, Nov. 30, 1972. 57 ABSTRACT [52] US. Cl. 180/44 R, 74/714 51 rm. c1 360k 17/34 Four Wheel mcludmg a transfer Case 5 m of Search 1 0/44 R 70 74/333 adapted to provide full time four wheel drive. A differ- 74/711 714, 368 ential is provided in the transfer case and, if desired,

the differential may be locked up to prevent differenti- [5 6] References Cited anon UNITED STATES PATENTS 3,295,625 1/1967 Ordorica et al 180/44 R 34 Claims, 2 Drawing Figures FULL TIME FOUR WHEEL DRIVE This a continuation of application Ser. No. 311,045 filed Nov. 30, 1972.

BACKGROUND OF THE INVENTION This invention relates to transfer cases for four wheel drive systems, and more particularly to a full time four wheel drive transfer case.

Four wheel drive systems have been in existence for many decades. The output of the engine was split between the front wheels and the rear wheels by a transfer case. One type of system used for many years provided undifferentiated power to all wheels of the vehicle. This gave the vehicle good mobility under adverse surface conditions. However, this type of drive was not particularly useful for normal highway driving. Since all four wheels operated at the same speed the vehicle could not be turned without sliding or scuffing one or more tires. This drawback resulted in the development of systems which included a conventional two wheel drive mechanism. For highway use the two wheel drive was utilized and this caused the vehicle to assume the characteristics of most other two wheel vehicles.

It is desirable in a four wheel drive vehicle to obtain the benefits of differentiation provided in conventional two wheel drive vehicles while also obtaining the benefits of a conventional four wheel drive, when desired. This invention is directed to a transfer case adapted to provide such characteristics.

BRIEF SUMMARY OF THE INVENTION Briefly, this invention comprises a transfer case adapted to provide a full time four wheel drive with or without differentiation of the drive to the front and rear axles.

One of the primary objects of this invention is to provide a transfer case which provides a full time four wheel drive at all times, both forward and reverse.

Another object of this invention is to provide a transfer case which permits the front axle to operate at a different speed than the rear axle.

A further object of this invention is to provide a transfer case of the class described which utilizes a differential adapted to be locked up to render the transfer case capable of providing a non-differentiating drive to the front and rear wheel sets.

Still another object of this invention is to provide a transfer case of the type described having a differential which may be easily and manually locked out to provide a positive drive to the front and rear sets of wheels, the lockout being accomplished without stopping the vehicle.

Another object of this invention is to provide a transfer case such as described in which the rear output shaft is on the same centerline as the input shaft, thereby eliminating the need for an offset rear axle. The power flow through the front train is thus one-half the torque relieving this train of excessive stress.

A further object of this invention is to provide a transfer case of the class described which is economical in construction and efficient in operation.

Other objects and advantages will be made apparent as the description progresses.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings, in which one of various possible embodiments is illustrated,

FIG. 1 is a section taken through a transfer case constructed in accordance with this invention; and

FIG. 2 is a diagrammatic view of the application of the transfer case shown in FIG. 1 to a truck.

Like parts are indicated by corresponding reference characters throughout the several views of the drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, a transfer case constructed in accordance with the invention is generally indicated at 1. The transfer-case 1 is shown in FIG. 2 as utilized in the drive train of a truck vehicle 3. The transmission output shaft 5 is connected to the transfer case 1 which feeds the power through a propshaft 7 to the axle 9, front wheels 11 and through a propshaft 13 to the axle 15 for the rear wheels 17.

The transfer case 1 includes a housing 19 formed in three sections 21, 24and 25 suitable interconnected by fasteners 27. An input shaft 29 is rotatably mounted in one wall 31 of housing 19 by bearings 33. Shaft 29 has an input low gear 35 formed integrally therewith which meshes with a larger gear 37 forming one gear of a gear cluster 39 rotatably journaled by bearing means 41 on a shaft 43 extending between wall 31 and a wall 45 of section 21. An annular lubricant trough or slinger 46 is provided on gear 37 adjacent the teeth thereof. The purpose of trough or slinger 46 will be made apparent hereinafter. Bearing means 41 incluses a first set 47 of roller bearings separated from a second set 49 of roller bearings by an annular spacer 51. Set 49 is separated from a third set 53 of bearings by a narrow annular spacer 55.

A second gear 57 of gear cluster 39 is spaced from gear 37 by a neck 59 having a plurality of radially extending lubricating ports 61 therein for facilitating the flow of lubricant to and from bearing means 41. Gear 57 is smaller than gear 37 and is in constant mesh with a gear 63 rotatably mounted on an elongated shaft 65 by a bushing 66. Gear 57 is also provided with a lubricating or slinger trough 58 and the gear teeth of gear 57 are slightly wider than the teeth of gear 63 for a purpose to be made apparent hereinafter.

The end of shaft 65 has a bore 67 therein in which the end 69 of shaft 29 is piloted. Bearings 71 rotatably support shaft 29. Clutching teeth 73 are formed on the outer periphery of shaft 65 and a clutch 75 surrounds and meshes with such teeth. Clutch 75 has a groove or recess 77 therein which receives an actuating yoke (not shown) for shifting the clutch to the right or left as viewed in FIG. 1. Shaft 29 is provided with clutching teeth 79 at its inner end adjacent gear 35. Troughs or ports, the bottoms of which are curved, are provided at Shaft 65 is supported by bearings 83 in a plate 85 mounted in wall 45 and a wall 87 of section 23 and extends rearwardly through section 23 and section 25. A collar 89 is splined at 91 to shaft 65 and has a plurality of pinion shafts 93 connected thereto and extending radially therefrom. Shafts 93 are secured at their outer ends in a carrier 95 of a differential unit 97 formed of two separate parts 99 and 101 and joined together by fasteners 103.

Pinions 105 are rotatably supported by shafts 93 on bearing sets and spacers 190 and 191, respectively, and are in mesh with two side gears 107 and 109, one of which has a tubular extension 111 and the other of which is formed on the end of an output shaft 113. Gear 107 and extension 111 are rotatably mounted on shaft 65 by a plurality of sets 115 of bearings separated by spacers 117.

Mounted on extension 111 by spline connection 119 is a sprocket 121. This sprocket is connected by a chain 123 to a front wheel drive sprocket 125 rotatably mounted by bearings 127 and 129 in section 123 of the three-part housing. The shaft 131 of sprocket 125 is spline connected to a yoke 133 which is adapted to be connected to the forwardly extending propshaft 7. A suitable seal is provided at 135.

The output shaft 113 is rotatably mounted by bearings 137 in the rearward end of section 25 of the housing. A collar 139 is splined at 141 to the shaft 113 and has a speedometer thread 143 thereon.

The speedometer thread 143 is located in a chamber 145 formed in section 25. Chamber 145 is adapted to be supplied with lubricant through pie-shaped openings 147 in wall 149. A breather fitting 148 is located on the outer wall of chamber 145 to permit operation with temperature and pressure variations.

A wall 149 is provided in section 25 and includes a hub 151 through which the shaft 113 extends. The opening through hub 151 has two portions, the first of which surrounds a lubricant feeding thread portion 154 of shaft 113. The lubricant feeding portion 153 has a thread 155 thereon for feeding lubricant from chamber 145 through the first portion of the opening in hub 151 toward the differential 97. A second portion of the opening in hub 151 surrounds bearings 157 which rotatably support the shaft 113. Radially extending lubricant ports or passages 159 are provided therein. Port 159 is located at the inward end of the lubricant feeding thread 155 and directs the oil to bore 163. Seal 192 behind bearing 157 prevents oil passage directly to bearing 157. The passage 159 extends radially inwardly to a bore 163 formed in the gear 109 and shaft 113. A first counterbore is provided at 165 and a second counterbore is provided at 167 in the gear 109 and shaft 113. The counterbore 165 pilots the right-hand end of the shaft 65 as viewed in FIG. 1. Bearings 169 rotatably support the end of shaft 65 in the counterbore 167.

An elongated passage 171 extends from one end of the shaft 65 to the other, placing the bore 67 in communication with the bore 163. Radial ports 159, 173 and 195 extend from passage 171 to the bearings 157, 115 and 169, respectively. As will be made apparent hereinafter, the various passages in the shafts provide for lubrication of the movable components of the transfer case.

The annular carrier 95, and particularly part 99 thereof, is provided with a set of annular internal clutch teeth 174 located outwardly of side gear 107. The

clutch hub 175 is splined at 177 to the extension 111 of side gear 107. Hub 175 has a set of external clutch teeth 179 adapted to be moved into meshing engagement with teeth 174. The clutch can be moved to the right by means of a manually operated yoke (not shown) extending into an annular groove or recess 18] in the hub. A coil spring 183 extends between a shoulder 185 in hub 175 and a retainer 187 positioned against the outer side of side gear 107. It will be seen that when the teeth 179 are moved into meshing engagement with the teeth 174 the carrier 95 is secured for rotation with the sprocket 121 through the hub 175 and extension 111.

The shaft 113 is connected by a yoke 189 to the rearwardly extending propshaft 13, thus providing a drive to the rear axle and wheels 15 and 17.

The yoke (not shown) which moves the hub 175 to the right as viewed in FIG. 1 is adapted to be locked in that position when the hub teeth 179 are in mesh with the teeth 174 so that spring 183 cannot force the hub teeth out of engagement with the carrier teeth.

Operation of the transfer case of this invention is as follows:

Assuming the various parts are as shown in FIG. 1, such as may occur when a power take-off unit is operative to drive other equipment, no drive is transferred from the input shaft 29 to the output shafts 113 or the forwardly extending stub shaft of sprocket 125. This is because clutch does not engage the shaft 65 with either gear 35 or gear 63. The input shaft 29 and gear 35 rotate the gear cluster 39 and this rotates the gear 63. However, since the gear 63 is rotatably mounted on shaft 65 no rotation is imparted to such shaft. Lubrication of the pilot bearings 71 is accomplished by means of the slinger 46. Lubricant is slung off the lip of the slinger or trough upwardly into the space between the teeth 79 and the face of shaft 65. The lubricant then flows into the bore 67 to the bearings 71. The lip of trough 58 and the ends of the teeth of gear 57 which extend beyond the ends of the teeth of gear 63 all act as slinger rings to sling lubricant up to the interface be tween clutch 75 and the face of teeth 83 and to diametrically opposed passages 84 for lubricating the bushing 66. If the clutch 75 is moved to the right the teeth thereof couple the teeth 73 and 83 of the shaft 65 and gear 63, respectively, thereby coupling the gear to the shaft. Accordingly, a low range drive is transmitted to the shaft 65 through the gear 35, gear cluster 39, gear 63 and clutch 75. The rotation of shaft 65 is imparted to the collar 89, and carrier through shafts 93. The differential 97 acts as a conventional differential and if the resistance to rotation of the front and rear wheels 11 and 17 is the same the carrier 95 and pinions rotate side gears 107 and 109 at the same rate and in the same direction. The side gear 107 drives the sprocket 121 through the spline connection 119, and the sprocket 121, through chain 123, drives the sprocket 125. Rotation of the sprocket is transmitted through yoke 133 and propshaft 7 to the differen' tial for the front axle 9. The differential for the front axle 9 permits differentiation between the two front wheels 11.

The drive to the differential for the rear axle 15 is transmitted from side gear 109, through shaft 113, coupling 189 and propshaft 13.

The level of lubricant in the transfer case may vary, but it is preferable that it be sufficiently high in the forward section 21 to permit the ingress and egress of lubricant through ports 193 and 194 of walls 87 and 31 of housing 21 into the bearings 47, 49 and 53 passing out through port 61 of gear 37. Lubricant is also pumped by threads 155 to port 159 and through the port to passage 171. From passage 171 lubricant flows through ports 173 to bearings 115 and through port 50 to bushing 66. Lubricant is also pumped by threads 155 through port 159 to elongated bore 171 to bearings 157 and therethrough port 195 to bearings 169 thence through port 161 to bearing 157.

Differentiation between front and rear axles is required when the front wheels of the vehicle travel in a different distance than the rear wheels, such as may occur in cornering, for example. Also, varying tire radii, due to load distribution or tire pressure, require different axle speeds. If the conditions are such that different axle speeds are required between the front and rear axles the differential 97 will differentiate to accomplish its specific mission. The side gear 107 rotates at a different speed than the side gear 109 to effect such different drive speeds to the axles.

Should conditions be such that it is desirable to mechanically lock up the differential, such as may occur in various severe situations involving the extreme off highway use or mudhole operation, for example, a rail shift lever (not shown) or cable (also not shown) is operated to move the hub 175 to the right as viewed in FIG. 1 until the teeth 179 engage teeth 174. This causes the differential to lock up and provide the same rotation to the front and rear output shafts.

it will be seen that the lubricating features of this invention, as well as the mechanical lock up system, provide a transfer case which is adapted to enhance the vehicle performance, durability and handling.

In view of the foregoing, it will be seen that the several objects and other advantages of this invention are achieved.

Although only one embodiment of the invention has been disclosed and described, it is apparent that other embodiments and modifications of the invention are possible.

I claim:

1. A transfer case for power drive systems comprising a housing, an input shaft, a rear wheel output shaft and a front wheel output shaft rotatably mounted in said housing, a differential carrier member, means for con necting said input shaft to said differential carrier member in a driving relationship, said means including an intermediate shaft member, a plurality of gear means adapted to connect said input shaft to said intermediate shaft member, a pinion member carried by said differential carrier member, first and second side gear members in mesh with said pinion member on opposite sides thereof to permit rotation of said side gear members at different speeds, means drivingly connecting said first side gear member to said front wheel output shaft, said second side gear member being connected to said rear wheel output shaft, and locking means drivingly and movably connected to one of said members and adapted to be moved between a first position out of engagement with one of said members and in which said differential carrier member may rotate relative to said side gear members and a second position in engagement with said one member for looking it to another one of said members for locking said intermediate shaft member differential carrier member, pinion member and side gear members together.

2. A transfer case as set forth in claim 1 wherein said plurality of gear means includes a first drive gear connected to said input shaft, a gear cluster having a second drive gear in constant mesh with said first drive gear and a third drive gear, a fourth drive gear, said intermediate shaft member mounting said fourth drive gear for rotation relative thereto, said third drive gear being in constant mesh with said fourth drive gear, said means for connecting said input shaft to said differential carrier member further including means connecting said intermediate shaft member to said differential carrier member, clutch means movable to three positions in one of which said first drive gear is coupled directly to said intermediate shaft member, in a second of which said fourth drive gear is coupled to said interme diate shaft member, and in a third of which said input shaft is not drivingly connected to said intermediate shaft member, bearing means rotatably supporting said input shaft in said intermediate shaft member, and lubricating means on said cluster gear for supplying lubricant to said bearing means when said clutch means is in said second and third positions.

3. A transfer case as set forth in claim 1 wherein said differential carrier member has a set of teeth formed annularly thereon, said locking means comprising a hub, said hub having an annular set of clutching teeth thereon, said hub being movable toward and away from said differential carrier member to move said clutch teeth into and out of engagement with the teeth on said differential carrier member.

4. A transfer case as set forth in claim 3 wherein said one side gear member has a tubular extension thereon, said means drivingly connecting said first side gear member to said front wheel output shaft includes said tubular extension, a sprocket splined to said tubular extension, said locking means including a hub, splines connecting said hub to said tubular extension, said teeth on said differential carrier member and said hub being adapted to be engaged upon movement of said hub in one direction to connect said differential carrier member to said tubular extension.

5. A transfer case as set forth in claim 4 further including a coil spring surrounding said tubular extension and extending between said first side gear member and said hub biasing said hub away from said differential carrier member.

6. A transfer case for power drive systems comprising a housing, an input shaft, a rear wheel output shaft and a front wheel output shaft rotatably mounted in said housing, a differential carrier, means for connecting said input shaft to said differential carrier in a driving relationship, a pinion carried by said differential carrier, first and second side gears in mesh with said pinion on opposite sides thereof to permit rotation of said side gears at different speeds, means drivingly connecting said first side gear to said front wheel output shaft, said second side gear being connected to said rear wheel output shaft, and locking means drivingly connected to one of said side gears adapted to be moved between a first position out of engagement with said differential carrier and in which said differential carrier may rotate relative to said side gears and a second position in engagement with said differential carrier for locking it to said one side gear for locking said differential carrier, pinions and side gears together.

7. A transfer case as set forth in claim 6 wherein said differential carrier has a set of teeth formed annularly thereon, said locking means comprising a hub, said hub having an annular set of clutching teeth thereon, said hub being movable toward and away from said differential carrier, to move said clutch teeth into and out of engagement with the teeth on said difierential carrier.

8. A transfer case as set forth in claim '7 further including a spring extending between said one side gear and said hub biasing the latter away from said differential carrier.

9. A transfer case as set forth in claim wherein said hub has an annular recess therein adapted to receive an actuating member for moving said hub.

10. A transfer case as set forth in claim 7 wherein said one side gear has a tubular extension thereon, said means drivingly connecting said first side gear to said front wheel output shaft includes said tubular extension, a sprocket splined to said tubular extension, said locking means including a hub, splines connecting said hub to said tubular extension, said teeth on said differential carrier and said hub being adapted to be engaged upon movement of said hub in one direction to connect said differential carrier to said tubular extension.

11. A transfer case as set forth in claim 10 further including a coil spring surrounding said tubular extension and extending between said first side gear and said hub biasing said hub away from said differential carrier.

12. A transfer case as set forth in claim 6 wherein said means for connecting said input shaft to said differential carrier includes a first drive gear connected to said input shaft, a gear cluster having a second drive gear in constant mesh with said first drive gear and a third drive gear, a fourth drive gear, an intermediate shaft mounting said fourth drive gear for rotation relative thereto, said third drive gear being in constant mesh with said fourth drive gear, means connecting said intermediate shaft to said differential carrier, clutch means movable to three positions in one of which said first drive gear is coupled directly to said intermediate shaft, in a second of which said fourth drive gear is coupled to said intermediate shaft and in a third of which said input shaft is not drivingly connected to said intermediate shaft, bearing means rotatably supporting said input shaft in said intermediate shaft, and lubricating means on said cluster gear for supplying lubricant to said bearing means when said clutch means is in said second and third positions.

13. A transfer case as set forth in claim 12 wherein said first gear is spaced axially from said intermediate shaft to provide a passage to said bearing means, said lubricating means including a trough on said second drive gear, said trough having a lip thereon adapted to direct lubricant from said trough toward said space.

14. A transfer case as set forth in claim 12 further comprising a bushing between said fourth drive gear and said intermediate shaft, and a slinger trough on said third drive gear, said slinger trough having a lip thereon adapted to direct lubricant from said slinger trough toward one end of said bushing.

15. A transfer case as set forth in claim 12 wherein the teeth of said third drive gear are wider than and extend outwardly beyond the ends of the teeth, a bushing between'said fourth drive gear and said intermediate shaft, the ends of the teeth of said third gear being adapted to direct lubricant toward opposite end portions of said bushing.

16. A transfer case as set forth in claim 12 wherein said differential carrier has a set of teeth formed annularly thereon, said locking means comprising a hub, said hub having an annular set of clutching teeth thereon, said hub being movable toward and away from said differential carrier, to move said clutch teeth into and out of engagement with the teeth on said differential carrier.

17. A transfer case as set forth in claim 16 further including a spring extending between said one side gear and said hub biasing the latter away from said differen' tial carrier.

18. A transfer case as set forth in claim 17 wherein said hub has an annular recess therein adapted to receive an actuating member for moving said hub.

19. A transfer case as set forth in claim l6 wherein said one side gear has a tubular extension thereon, said means drivingly connecting said first side gear to said front wheel output shaft includes said tubular extension, a sprocket splined to said tubular extension, said locking means including a hub, splines connecting said hub to said tubular extension, said teeth on said differential carrier and said hub adapted to be engaged upon movement of said hub in one direction to connect said differential carrier to said tubular extension.

20. A full time four wheel drive for a vehicle comprising a front axle, a rear axle, a power train including a first output shaft, a transfer case, said transfer case having an input shaft, a rear wheel output shaft and a front wheel output shaft, a rear propshaft connected at one end to said rear wheel output shaft and at its other end to said rear axle, a forward propshaft connected at one end to said front wheel output shaft and at its other end to said front axle, said transfer case including a differ ential carrier member, means for connecting said input shaft to said differential carrier member in a driving relationship, said means including an intermediate shaft member, a pinion carried by said differential carrier member, first and second side gear members in mesh with said pinion member on opposite sides thereof to permit rotation of said side gear member at different speeds, means drivingly connecting said first side gear member to said front wheel output shaft, said second side gear member being connected to said rear wheel output shaft, and locking means drivingly and movably connected to one of said side gear members and adapted to be moved between a first position out of engagement with one of said members and in which said differential carrier member may rotate relative to said side gear members and a second position in engagement with said one member for locking it to another one of said members for locking said intermediate shaft member differential carrier member, pinion member and side gear members together.

21. A full time four wheel drive as set forth in claim 26 wherein said differential carrier member has a set of teeth formed annularly thereon, said locking means comprising a hub, said hub having an annular set of clutching teeth thereon, said hub being movable toward and away from said differential carrier member, to move said clutch teeth into and out of emgagement with the teeth on said differential carrier member.

22. A full time four wheel drive asset forth in claim 21 further including a spring extending between said one side gear member and said hub biasing the latter away from said differential carrier member.

23. A full time four wheel drive as set forth in claim 21 wherein said one side gear member has a tubular extension thereon, said means drivingly connecting said first side gear member to said front wheel output shaft includes said tubular extension, a sprocket splined to said tubular extension, said locking means including a hub, splines connecting said hub to said tubular extension, said teeth on said differential carrier member and said hub adapted to be engaged upon movement of said hub in one direction to connect said differential carrier member to said tubular extension.

24. A full time four wheel drive as set forth in claim wherein said means for connecting said input shaft to said differential carrier member includes a first drive gear connected to said input shaft, a gear cluster having a second drive gear in constant mesh with said first drive gear and a third drive gear, a fourth drive gear, said intermediate shaft mounting said fourth drive gear for rotation relative thereto, said third drive gear being in constant mesh with said fourth drive gear, means connecting said intermediate shaft to said differential carrier member, clutch means movable to three positions in one of which said first drive gear is coupled directly to said intermediate shaft member, in a second of which said fourth drive gear is coupled to said intermediate shaft member and in a third of which said input shaft is not drivingly connected to said intermediate shaft member, bearing means rotatably supporting said input shaft in said intermediate shaft member, and lubricating means on said cluster gear for supplying lubricant to said bearing means when said clutch means is in said second and third positions.

25. A full time four wheel drive as set forth in claim 24 wherein said first drive gear is spaced axially from said intermediate shaft to provide a passage to said bearing means, said lubricating means including a slinger on said second drive gear adapted to direct lubricant from said slinger toward said space.

26. A full time four wheel drive as set forth in claim 24 wherein said differential carrier member has a set of teeth formed annularly thereon, said locking means comprising a hub, said hub having an annular set of clutching teeth thereon, said hub being movable toward and away from said differential carrier member to move said clutch teeth into and out of engagement with the teeth on said differential carrier member.

27. A full time four wheel drive as set forth in claim 25 further including a spring extending between said one side gear member and said hub biasing the latter away from said differential carrier member.

28. A transfer case for power drive systems comprising a housing, an input shaft, a rear wheel output shaft and a front wheel output shaft rotatably mounted in said housing, a differential carrier member, means for connecting said input shaft to said differential carrier member in a driving relationship, said means including an intermediate shaft member, a plurality of gear means adapted to connect said input shaft to said intermediate shaft member, a pinion member carried by said differential carrier member, first and second side gear members in mesh with said pinion member on opposite sides thereof to permit rotation of said side gear members at different speeds, means drivingly connecting said first side gear member to said front wheel output shaft, said second side gear member being connected to said rear wheel output shaft, and rotation inhibiting means for inhibiting the rotation of one of said side gear members relative to the other, said rotation inhibiting means being connected to and between two of said members and having first and second operative conditions, the first operative condition of said rotation inhibiting means being one in which said differential carrier member may rotate relative to said gear members, said second operative condition of said rotation inhibiting means being one in which rotation of said differential carrier member relative to said side gears is inhibited for inhibiting the relative rotation between said intermediate shaft, said differential carrier member, said pinion member and said side gear members.

29. A transfer case as set forth in claim 28 wherein said plurality of gear means includes a first drive gear connected to said input shaft, a gear cluster having a second drive gear in constant mesh with said first drive gear and a third drive gear, a fourth drive gear, said intermediate shaft member mounting said fourth drive gear for rotation relative thereto, said third drive gear being in constant mesh with said fourth drive gear, said means for connecting said input shaft to said differential carrier member further including means connecting said intermediate shaft member to said differential carrier member, clutch means movable to three positions in one of which said first drive gear is coupled directly to said intermediate shaft member, in a second of which said fourth drive gear is coupled to said intermediate shaft member, and in a third of which said input shaft is not drivingly connected to said intermediate shaft member, bearing means rotatably supporting said input shaft in said intermediate shaft member, and lubricating means on said cluster gear for supplying lubricant to said bearing means when said clutch means is in said second and third positions.

30. A full time four wheel drive for a vehicle comprising a front axle, a rear axle, a power train including a first output shaft, a transfer case, said transfer case having an input shaft, a rear wheel output shaft and a front wheel output shaft, a rear propshaft connecting at one end to said rear wheel output shaft and at its other end 1 to said rear axle, a forward propshaft connected at one end to said front wheel output shaft and at its other end to said front axle, said transfer case including a differential carrier member, means for connecting said input shaft to said differential carrier member in a driving relationship, said means including an intermediate shaft member, a pinion carried by said differential carrier member, first and second side gear members in mesh with said pinion member on opposite sides thereof to permit rotation of said side gear member at different speeds, means drivingly connecting said first side gear member to said front wheel output shaft, said second side gear member being connected to said rear wheel output shaft, and rotation inhibiting means for inhibiting the rotation of one of said side gear members relative to the other, said rotation inhibiting means being connected to and between two of said members and having first and second operative conditions, the first operative condition of said rotation inhibiting means being one in which said differential carrier member may rotate relative to said gear members, said second operative condition of said rotation inhibiting means being one in which rotation of said differential carrier member relative to said side gears is inhibited for inhibiting the relative rotation between said intermediate shaft, said differential carrier member, said pinion member and said side gear members.

31. A full time four wheel drive as set forth in claim 30 wherein said means for connecting said input shaft to said differential carrier member includes a first drive gear connected to said input shaft, a gear cluster having a second drive gear in constant mesh with said first drive gear and a third drive gear, a fourth drive gear, said intermediate shaft mounting said fourth drive gear for rotation relative thereto, said third drive gear being in constant mesh with said fourth drive gear, means connecting said intermediate shaft to said differential carrier member, clutch means movable to three positions in one of which said first drive gear is coupled directly to said intermediate shaft member, in a second of which said fourth drive gear is coupled to said intermediate shaft member and in a third of which said input shaft is not drivingly connected to said intermediate shaft member, bearing means rotatably supporting said input shaft in said intermediate shaft member, and lubricating means on said cluster gear for supplying lubricant to said bearing means when said clutch means is in said second and third positions.

32. A full time four wheel drive as set forth in claim 31 wherein said first drive gear is spaced axially from said intermediate shaft to provide a passage to said bearing means, said lubricating means including a slinger on said second drive gear adapted to direct lubricant from said slinger toward said space.

33. A transfer case for power drive systems comprising a housing, an input shaft, a rear wheel output shaft and a front wheel output shaft rotatably mounted in said housing, a differential carrier member, means for connecting said input shaft to said differential carrier member in a driving relationship for rotation around an axis, a pinion member carried by said differential carrier member, first and second side gear members rotatable around said axis and in mesh with said pinion member on opposite sides thereof to permit rotation of said side gear members at different speeds, means drivingly connecting said first side gear member to said front wheel output shaft, said second side gear member being connected to said rear wheel output shaft, and rotation inhibiting means for inhibiting the rotation of one of said side gear members relative to the other, said rotation inhibiting means being connected to and between two of said members and having first and second operative conditions, said rotation inhibiting means being rotatable around said axis and spaced radially outwardly from at least one of said side gear members, the first operative condition of said rotation inhibiting means being one in which said differential carrier member may rotate relative to said gear members, said second operative condition of said rotation inhibiting means being one in which rotation of said differential carrier member relative to said side gears is inhibited for inhibiting the relative rotation between said input shaft, said differential carrier member, said pinion member and said side gear members.

34. A transfer case as set forth in claim 33 wherein said rotation inhibiting means includes two sets of driving elements, one set of said driving element being connected for rotation with one of said members and the second set of said driving elements being connected to another of said members, said elements drivingly cooperating with one another when said rotation inhibiting means is in said second operative condition. 

1. A transfer case for power drive systems comprising a housing, an input shaft, a rear wheel output shaft and a front wheel output shaft rotatably mounted in said housing, a differential carrier member, means for connecting said input shaft to said differential carrier member in a driving relationship, said means including an intermediate shaft member, a plurality of gear means adapted to connect said input shaft to said intermediate shaft member, a pinion member carried by said differential carrier member, first and second side gear members in mesh with said pinion member on opposite sides thereof to permit rotation of said side gear members at different speeds, means drivingly connecting said first side gear member to said front wheel output shaft, said second side gear member being connected to said rear wheel output shaft, and locking means drivingly and movably connected to one of said members and adapted to be moved between a first position out of engagement with one of said members and in which said differential carrier member may rotate relative to said side gear members and a second position in engagement with said one member for locking it to another one of said members for locking said intermediate shaft member differential carrier member, pinion member and side gear members together.
 2. A transfer case as set forth in claim 1 wherein said plurality of gear means includes a first drive gear connected to said input shaft, a gear cluster having a second drive gear in constant mesh with said first drive gear and a third drive gear, a fourth drive gear, said intermediate shaft member mounting said fourth drive gear for rotation relative thereto, said third drive gear being in constant mesh with said fourth drive gear, said means for connecting said input shaft to said differential carrier member further including means connecting said intermediate shaft member to said differential carrier member, clutch means movable to three positions in one of which said first drive gear is coupled directly to said intermediate shaft member, in a second of which said fourth drive gear is coupled to said intermediate shaft member, and in a third of which said input shaft is not drivingly connected to said intermediate shaft member, bearing means rotatably supporting said input shaft in said intermediate shaft member, and lubricating means on said cluster gear for supplying lubricant to said bearing means when said clutch means is in said second and third positions.
 3. A transfer case as set forth in claim 1 wherein said differential carrier member has a set of teeth formed annularly thereon, said locking means comprising a hub, said hub having an annular set of clutching teeth thereon, said hub being movable toward and away from said differential carrier member to move said clutch teeth into and out of engagement with the teeth on said differential carrier member.
 4. A transfer case as set forth in claim 3 wherein said one side gear member has a tubular extension thereon, said means drivingly connecting said first side gear member to said front wheel output shaft includes said tubular extension, a sprocket splined to said tubular extension, said locking means including a hub, splines connecting said hub to said tubular extension, said teeth on said differential carrier member and said hub being adapted to be engaged upon movement of said hub in one direction to connect said differential carrier member to said tubular extension.
 5. A transfer case as set forth in claim 4 further including a coil spring surrounding said tubular extension and extending between said first side gear member and said hub biasing said hub away from said differential carrier member.
 6. A transfer case for power drive systems comprising a housing, an input shaft, a rear wheel output shaft and a front wheel output shaft rotatably mounted in said housing, a differential carrier, means for connecting said Input shaft to said differential carrier in a driving relationship, a pinion carried by said differential carrier, first and second side gears in mesh with said pinion on opposite sides thereof to permit rotation of said side gears at different speeds, means drivingly connecting said first side gear to said front wheel output shaft, said second side gear being connected to said rear wheel output shaft, and locking means drivingly connected to one of said side gears adapted to be moved between a first position out of engagement with said differential carrier and in which said differential carrier may rotate relative to said side gears and a second position in engagement with said differential carrier for locking it to said one side gear for locking said differential carrier, pinions and side gears together.
 7. A transfer case as set forth in claim 6 wherein said differential carrier has a set of teeth formed annularly thereon, said locking means comprising a hub, said hub having an annular set of clutching teeth thereon, said hub being movable toward and away from said differential carrier, to move said clutch teeth into and out of engagement with the teeth on said differential carrier.
 8. A transfer case as set forth in claim 7 further including a spring extending between said one side gear and said hub biasing the latter away from said differential carrier.
 9. A transfer case as set forth in claim 8 wherein said hub has an annular recess therein adapted to receive an actuating member for moving said hub.
 10. A transfer case as set forth in claim 7 wherein said one side gear has a tubular extension thereon, said means drivingly connecting said first side gear to said front wheel output shaft includes said tubular extension, a sprocket splined to said tubular extension, said locking means including a hub, splines connecting said hub to said tubular extension, said teeth on said differential carrier and said hub being adapted to be engaged upon movement of said hub in one direction to connect said differential carrier to said tubular extension.
 11. A transfer case as set forth in claim 10 further including a coil spring surrounding said tubular extension and extending between said first side gear and said hub biasing said hub away from said differential carrier.
 12. A transfer case as set forth in claim 6 wherein said means for connecting said input shaft to said differential carrier includes a first drive gear connected to said input shaft, a gear cluster having a second drive gear in constant mesh with said first drive gear and a third drive gear, a fourth drive gear, an intermediate shaft mounting said fourth drive gear for rotation relative thereto, said third drive gear being in constant mesh with said fourth drive gear, means connecting said intermediate shaft to said differential carrier, clutch means movable to three positions in one of which said first drive gear is coupled directly to said intermediate shaft, in a second of which said fourth drive gear is coupled to said intermediate shaft and in a third of which said input shaft is not drivingly connected to said intermediate shaft, bearing means rotatably supporting said input shaft in said intermediate shaft, and lubricating means on said cluster gear for supplying lubricant to said bearing means when said clutch means is in said second and third positions.
 13. A transfer case as set forth in claim 12 wherein said first gear is spaced axially from said intermediate shaft to provide a passage to said bearing means, said lubricating means including a trough on said second drive gear, said trough having a lip thereon adapted to direct lubricant from said trough toward said space.
 14. A transfer case as set forth in claim 12 further comprising a bushing between said fourth drive gear and said intermediate shaft, and a slinger trough on said third drive gear, said slinger trough having a lip thereon adapted to direct lubricant from said slinger trough toward one end of said bushing.
 15. A traNsfer case as set forth in claim 12 wherein the teeth of said third drive gear are wider than and extend outwardly beyond the ends of the teeth, a bushing between said fourth drive gear and said intermediate shaft, the ends of the teeth of said third gear being adapted to direct lubricant toward opposite end portions of said bushing.
 16. A transfer case as set forth in claim 12 wherein said differential carrier has a set of teeth formed annularly thereon, said locking means comprising a hub, said hub having an annular set of clutching teeth thereon, said hub being movable toward and away from said differential carrier, to move said clutch teeth into and out of engagement with the teeth on said differential carrier.
 17. A transfer case as set forth in claim 16 further including a spring extending between said one side gear and said hub biasing the latter away from said differential carrier.
 18. A transfer case as set forth in claim 17 wherein said hub has an annular recess therein adapted to receive an actuating member for moving said hub.
 19. A transfer case as set forth in claim 16 wherein said one side gear has a tubular extension thereon, said means drivingly connecting said first side gear to said front wheel output shaft includes said tubular extension, a sprocket splined to said tubular extension, said locking means including a hub, splines connecting said hub to said tubular extension, said teeth on said differential carrier and said hub adapted to be engaged upon movement of said hub in one direction to connect said differential carrier to said tubular extension.
 20. A full time four wheel drive for a vehicle comprising a front axle, a rear axle, a power train including a first output shaft, a transfer case, said transfer case having an input shaft, a rear wheel output shaft and a front wheel output shaft, a rear propshaft connected at one end to said rear wheel output shaft and at its other end to said rear axle, a forward propshaft connected at one end to said front wheel output shaft and at its other end to said front axle, said transfer case including a differential carrier member, means for connecting said input shaft to said differential carrier member in a driving relationship, said means including an intermediate shaft member, a pinion carried by said differential carrier member, first and second side gear members in mesh with said pinion member on opposite sides thereof to permit rotation of said side gear member at different speeds, means drivingly connecting said first side gear member to said front wheel output shaft, said second side gear member being connected to said rear wheel output shaft, and locking means drivingly and movably connected to one of said side gear members and adapted to be moved between a first position out of engagement with one of said members and in which said differential carrier member may rotate relative to said side gear members and a second position in engagement with said one member for locking it to another one of said members for locking said intermediate shaft member differential carrier member, pinion member and side gear members together.
 21. A full time four wheel drive as set forth in claim 20 wherein said differential carrier member has a set of teeth formed annularly thereon, said locking means comprising a hub, said hub having an annular set of clutching teeth thereon, said hub being movable toward and away from said differential carrier member, to move said clutch teeth into and out of emgagement with the teeth on said differential carrier member.
 22. A full time four wheel drive as set forth in claim 21 further including a spring extending between said one side gear member and said hub biasing the latter away from said differential carrier member.
 23. A full time four wheel drive as set forth in claim 21 wherein said one side gear member has a tubular extension thereon, said means drivingly connecting said first side gear member to said front wheel output shaft includes said tubular extension, a sProcket splined to said tubular extension, said locking means including a hub, splines connecting said hub to said tubular extension, said teeth on said differential carrier member and said hub adapted to be engaged upon movement of said hub in one direction to connect said differential carrier member to said tubular extension.
 24. A full time four wheel drive as set forth in claim 20 wherein said means for connecting said input shaft to said differential carrier member includes a first drive gear connected to said input shaft, a gear cluster having a second drive gear in constant mesh with said first drive gear and a third drive gear, a fourth drive gear, said intermediate shaft mounting said fourth drive gear for rotation relative thereto, said third drive gear being in constant mesh with said fourth drive gear, means connecting said intermediate shaft to said differential carrier member, clutch means movable to three positions in one of which said first drive gear is coupled directly to said intermediate shaft member, in a second of which said fourth drive gear is coupled to said intermediate shaft member and in a third of which said input shaft is not drivingly connected to said intermediate shaft member, bearing means rotatably supporting said input shaft in said intermediate shaft member, and lubricating means on said cluster gear for supplying lubricant to said bearing means when said clutch means is in said second and third positions.
 25. A full time four wheel drive as set forth in claim 24 wherein said first drive gear is spaced axially from said intermediate shaft to provide a passage to said bearing means, said lubricating means including a slinger on said second drive gear adapted to direct lubricant from said slinger toward said space.
 26. A full time four wheel drive as set forth in claim 24 wherein said differential carrier member has a set of teeth formed annularly thereon, said locking means comprising a hub, said hub having an annular set of clutching teeth thereon, said hub being movable toward and away from said differential carrier member to move said clutch teeth into and out of engagement with the teeth on said differential carrier member.
 27. A full time four wheel drive as set forth in claim 25 further including a spring extending between said one side gear member and said hub biasing the latter away from said differential carrier member.
 28. A transfer case for power drive systems comprising a housing, an input shaft, a rear wheel output shaft and a front wheel output shaft rotatably mounted in said housing, a differential carrier member, means for connecting said input shaft to said differential carrier member in a driving relationship, said means including an intermediate shaft member, a plurality of gear means adapted to connect said input shaft to said intermediate shaft member, a pinion member carried by said differential carrier member, first and second side gear members in mesh with said pinion member on opposite sides thereof to permit rotation of said side gear members at different speeds, means drivingly connecting said first side gear member to said front wheel output shaft, said second side gear member being connected to said rear wheel output shaft, and rotation inhibiting means for inhibiting the rotation of one of said side gear members relative to the other, said rotation inhibiting means being connected to and between two of said members and having first and second operative conditions, the first operative condition of said rotation inhibiting means being one in which said differential carrier member may rotate relative to said gear members, said second operative condition of said rotation inhibiting means being one in which rotation of said differential carrier member relative to said side gears is inhibited for inhibiting the relative rotation between said intermediate shaft, said differential carrier member, said pinion member and said side gear members.
 29. A transfer case as set forth in claim 28 whereIn said plurality of gear means includes a first drive gear connected to said input shaft, a gear cluster having a second drive gear in constant mesh with said first drive gear and a third drive gear, a fourth drive gear, said intermediate shaft member mounting said fourth drive gear for rotation relative thereto, said third drive gear being in constant mesh with said fourth drive gear, said means for connecting said input shaft to said differential carrier member further including means connecting said intermediate shaft member to said differential carrier member, clutch means movable to three positions in one of which said first drive gear is coupled directly to said intermediate shaft member, in a second of which said fourth drive gear is coupled to said intermediate shaft member, and in a third of which said input shaft is not drivingly connected to said intermediate shaft member, bearing means rotatably supporting said input shaft in said intermediate shaft member, and lubricating means on said cluster gear for supplying lubricant to said bearing means when said clutch means is in said second and third positions.
 30. A full time four wheel drive for a vehicle comprising a front axle, a rear axle, a power train including a first output shaft, a transfer case, said transfer case having an input shaft, a rear wheel output shaft and a front wheel output shaft, a rear propshaft connecting at one end to said rear wheel output shaft and at its other end to said rear axle, a forward propshaft connected at one end to said front wheel output shaft and at its other end to said front axle, said transfer case including a differential carrier member, means for connecting said input shaft to said differential carrier member in a driving relationship, said means including an intermediate shaft member, a pinion carried by said differential carrier member, first and second side gear members in mesh with said pinion member on opposite sides thereof to permit rotation of said side gear member at different speeds, means drivingly connecting said first side gear member to said front wheel output shaft, said second side gear member being connected to said rear wheel output shaft, and rotation inhibiting means for inhibiting the rotation of one of said side gear members relative to the other, said rotation inhibiting means being connected to and between two of said members and having first and second operative conditions, the first operative condition of said rotation inhibiting means being one in which said differential carrier member may rotate relative to said gear members, said second operative condition of said rotation inhibiting means being one in which rotation of said differential carrier member relative to said side gears is inhibited for inhibiting the relative rotation between said intermediate shaft, said differential carrier member, said pinion member and said side gear members.
 31. A full time four wheel drive as set forth in claim 30 wherein said means for connecting said input shaft to said differential carrier member includes a first drive gear connected to said input shaft, a gear cluster having a second drive gear in constant mesh with said first drive gear and a third drive gear, a fourth drive gear, said intermediate shaft mounting said fourth drive gear for rotation relative thereto, said third drive gear being in constant mesh with said fourth drive gear, means connecting said intermediate shaft to said differential carrier member, clutch means movable to three positions in one of which said first drive gear is coupled directly to said intermediate shaft member, in a second of which said fourth drive gear is coupled to said intermediate shaft member and in a third of which said input shaft is not drivingly connected to said intermediate shaft member, bearing means rotatably supporting said input shaft in said intermediate shaft member, and lubricating means on said cluster gear for supplying lubricant to said bearing means when said clutch means is in said second and thiRd positions.
 32. A full time four wheel drive as set forth in claim 31 wherein said first drive gear is spaced axially from said intermediate shaft to provide a passage to said bearing means, said lubricating means including a slinger on said second drive gear adapted to direct lubricant from said slinger toward said space.
 33. A transfer case for power drive systems comprising a housing, an input shaft, a rear wheel output shaft and a front wheel output shaft rotatably mounted in said housing, a differential carrier member, means for connecting said input shaft to said differential carrier member in a driving relationship for rotation around an axis, a pinion member carried by said differential carrier member, first and second side gear members rotatable around said axis and in mesh with said pinion member on opposite sides thereof to permit rotation of said side gear members at different speeds, means drivingly connecting said first side gear member to said front wheel output shaft, said second side gear member being connected to said rear wheel output shaft, and rotation inhibiting means for inhibiting the rotation of one of said side gear members relative to the other, said rotation inhibiting means being connected to and between two of said members and having first and second operative conditions, said rotation inhibiting means being rotatable around said axis and spaced radially outwardly from at least one of said side gear members, the first operative condition of said rotation inhibiting means being one in which said differential carrier member may rotate relative to said gear members, said second operative condition of said rotation inhibiting means being one in which rotation of said differential carrier member relative to said side gears is inhibited for inhibiting the relative rotation between said input shaft, said differential carrier member, said pinion member and said side gear members.
 34. A transfer case as set forth in claim 33 wherein said rotation inhibiting means includes two sets of driving elements, one set of said driving element being connected for rotation with one of said members and the second set of said driving elements being connected to another of said members, said elements drivingly cooperating with one another when said rotation inhibiting means is in said second operative condition. 